The present invention is related to machines used in performing railway right-of-way maintenance, and specifically to a machine for driving railroad spikes into railroad track ties using pushing and/or percussive forces.
Conventional railroad spike driving machines are commonly provided in one of two configurations. The first configuration, referred to as a pusher type spiker, includes a hydraulic ram used for pushing the individual spikes into the railroad tie under constant pressure. The second configuration, referred to as a percussive type spiker, involves a percussive system which uses a vertically reciprocating hammer to drive the spike by repeated blows.
Both the pusher and percussive configurations have specific advantages and disadvantages. While the push type spiker is capable of driving relatively more spikes per minute than the percussive type spiker, the latter is more effective in driving spikes in difficult applications.
Instances where the percussive type spiker is more effective include track sections where the ties are made of relatively hard wood, or where recycled spikes are being used to refurbish the rail bed. Recycled spikes often include bent spikes, which, if driven by a push type spiker, may be bent more severely. The relatively greater amount of driving force applied by the percussive type spiker avoids this unwanted additional bending of the spikes, and also drives spikes farther into the tie than is possible with push type spikers. Also, the push type spiker is significantly quieter than the percussive type machine, and as such is more desirable from the operator's perspective, especially in view of the fact that spike driving machines are operated for extended periods of time.
An object of the present invention is to provide a rail spike driver or spiker machine having the capability to drive spikes using both the pusher and percussive functions.
Another object of the present invention is to provide a combination push/percussive spiker in which both functions are performed by a single unit.
Yet another object of the present invention is to provide a combination push/percussive spiker which features selectable variability between pushing and percussing functions.
An additional object of the present invention is to provide a combination push/percussive spiker which is compatible with existing spike driving equipment.